NEW YORK — This fall brings a number of opportunities to see celebrated actors juggle multiple personalities on Broadway. There's Mark Rylance, playing Twelfth Night's Olivia and Richard III in rep, while his fellow Brits Ian McKellen and Patrick Stewart tackle 20th-century classics No Man's Land and Waiting for Godot.

But only a Yank had the audacity to take on eight roles in a single production — all of them Englishmen, incidentally. That's Jefferson Mays, whose shape-shifting and comedic gifts are on glorious display in A Gentleman's Guide to Love & Murder (***½ out of four stars), the delightful new musical romp that opened Sunday at the Walter Kerr Theatre, following acclaimed runs at Hartford (Conn.) Stage and San Diego's Old Globe.

Mays, who earned a Tony Award fielding an even greater number of characters in 2003's I Am My Own Wife, plays various members of a noble family in Edwardian England. The D'Ysquiths include the pompous Lord Adalbert, the dramatic Lady Salome, the charitable matron Lady Hyacinth, the fitness-obsessed Major Lord Bartholomew and an eccentric beekeeper named Henry.

They all have one thing in common: A young interloper named Monty Navarro wants them dead. Having learned that his late mother was also a D'Ysquith, but was disinherited when she eloped with an unsuitable man, this ambitious fellow aspires to become Earl of Highhurst by offing everyone else in line.

Monty is also the narrator; we meet him as he is awaiting trial, then hear him recount his dastardly deeds. Under Darko Tresnjak's witty direction — supported by the drolly imaginative scenic and projection design of Alexander Dodge and Aaron Rhyne, respectively — a series of morbidly hilarious events unfolds, involving simulated cracked ice, spilling pools of red and shadows of hysterical people running back and forth.

Mays is as funny evoking the characters' often-grisly ends as he is giving them quirky life. The buff, blustering major is undone by his machismo, while poor, delicate Henry — whose particular fondness for Monty informs the side-splitting duet Better with a Man, one of several catchy, clever songs by composer/lyricist Steven Lutvak and lyricist/librettist Robert L. Freedman — finds his beloved little buzzers turned unwittingly against him.

Lady Hyacinth, perhaps toughened by her efforts on behalf of the less fortunate — "We met last month at the Consumptives Ball," Monty tells her, by way of introduction — proves more resilient, but Monty remains undaunted.

The actor who plays Monty, Bryce Pinkham, is pretty of voice and bone structure, but not a natural comic performer. He loosens up nicely as Guide progresses, though, and receives ample support from a sassy Lisa O'Hare and crystalline-voiced Lauren Worsham, as Monty's rival love interests.

Ultimately, of course, this is Mays' show — and he seems to have as grand a time carrying it as you will watching him.